Double-wall pipe.



C. M. BULLER.

DOUBLE WALL PIPE.

APPLICATION FILED SEPT. 25. me.

Patented Apr. 8,1919..

"ToaZZ iokmieit may com f 1 Be it known that I, CHARLES M. BULLER emamsnfienttea', or MILWAUKEE,fwisco sisinfnssieivonTon-J;iyliiEIiLEnfQ FURNACE GOMPANYLOF MILWAUKEE, IscoNsImn iconroimrion oFzWIS- coNsIN. l j

. 7 a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of Wisconsin, have lnvented new and useful Improvements in Doubler'Wall Pipes, of whichthefollo'wingis a,descrip ,tion, reference beinglhadto the accompanying drawings, whichare a part of this specification. i

This invention relates to improvements in hot air pipes more furnace use. c. Furnace pipes of the modern type are usually formed of double wall construction and in sections of a length convenient to cut from the sheet metal and to handle and as f semble. The two walls are spaced apart to 7 form an insulating air-space therebetween" to increase the heat conductivity of the inner pipe and prevent waste ofheat. Pipe sec tions of this type areusually factory made and provided with overlapping interlocking ,and which is of inexpensive and efii'cient constructlon.

joints and arejointedtogether at the place of installationto form pipes .of the proper gether. g I It is one of the objectsof the presentinvention to provide a doublerwall pipewhichhas the before-mentioned desirable features .A further object adjustably'con'nected together.

vide a double wall pipe'having a joint construction which will "permit the trimming of. one of the ends of one of the sections to adjust the length: of the assembled sections? toa predetermined height. I

A further object of the invention is to pro-" vide a double wall pipe in which the corner portions are constructed in a'manner tore:

inforce the parts.

particularly adapted for t of the invention is to? provide a double wall pipe havingsectio'nsf vwhich may be easily superposed aboveian -j. other section through the medium of an im-jroved joint to permit-i the sections to be A further object of the invention is to prosection placed thereon. V

DOU LE-WALL mm is Well'adapted for thepurpose described.

as setfort hin the claims-, and all equivalents thereof.

I e 11919;? Animation filed sptegiber 1 seam. 255,715. v

I l 1Aiefurther,obiectof the invention: islto ssr f, T providela double 'P pe which isof S1311 ,.p1 construction, ;is strong andcdurable and In the acconipanying drawing in,

the same reference characters indicate the same parts in all of the views:

. Figure Li s a side-view of a plurality of Y 7 sections ofthe improved doublejwall pipe, A

parts being shown in section;-

Fig. 2. 1s a vertlcal sectionaludetail .view',

on a.larger.scale,ftaken on line 27-2 of Fig.

Fig. 3 is atransverse.sectional'view taken on line' 3 ;'3 of Fig. 1.

. Reiierripg to the drawing, the *nunierals i and 6 indicate two of thepip'e sections which are 'constructedin-a-novel manner'to provide theimproved'adjustablegjoint fto be later 7 describediffEach pipe sectionisof reetangu- Y lar fQPm'l'ILCIiOSS section'and consists'pfan 3 0' innerwall 8 and an outer'wall;9';connectd together.{-in "spaced relation 'to forth a in sulating air-space l0 :betweencsaidflwalls. v 'Said inner and outer. walls? areformed of ieces of sheet metal joinedtogetheralong their vertical-edge portions .toi form the corner edges of the pipe;- by v interlocking. I V la ped joi ntsj 8. and? 9 wliichf provide for the convenientmanufactureeof thesections and materiallyincrease the strengthTofsaid g section 1v 'The,.;lower endi'portio i's ofjthe'fin i ner walls- 8 offthe, section 5 *are'ibent in-.

wardlytofformstop shoulders 11 andyare then-bent outwardlyin a series of angles 12 5' to join 'the finnerrand outenwallstogether as'fiindicatedby the numeral lj3ii Theiop;

posite end portions of the said connected.

' .together'ends-Barebentinwardly tef rmg: 1

the upperend of the section: 5 by inclining f locking shoulders 1% which "are adap't ed? to snapover cowacting'shoulders 15' formedon theouter'wall inwardly in a series of angles v, '16 to connect'the upper endiportions of saidf walls'together: The co-acting shouldersl5 at theuopp'osite "side portion sjof the pipe serveasgmde and spacingportions "for the v overlapping lower endportion'syof thepipe i 3 a The-" conriec'ting pore a 1';

tions 16 of the outer wall are also bent outwardly to form outer stop shoulders 17. The outer stop shoulders 17 are engaged by the lowerend portions of the outer walls of the 16 are'provided with apertures 12 and 16 to permit air circulation therethrough.

The upper portions of the pipe section 5 are similar to the upper portions of the p1pe section 5. with the exception that instead of the inwardly bent portions 16 of the outerwall directly engaging the inner wall, independent U-shaped spacing members 18 are interposed between the two walls and the upper edges of said members 18 are bent over to form overlapping engagements with the upper edges of the inner and outer walls.

Said U-shaped spacing members form elongated grooves'or recesses 19 forreceiving the lower end portions of the inner wall 8 of the adjustable upper section 6. The lower end portions of the-inner and the outer walls of the upper section 6 extend downwardly in straight lines and are not attached to each other so that the inner wall portions 8 can be inserted into the grooves 19 and the outerwall portions 9 can overlap or telescope the angular inwardly bent portions 16*of the outer wall 9 of the secti0n'5. The inner wall 80f the section 6 projects below the outer wall 9 to conveniently expose to view the inner walls of both sections while slipping said inner walls together. The straight lower portions of the inner and outer walls and the projection of the inner wall below the outer wall also provides for conveniently cutting or trimmingboth lower edge-portions to secure the desired height of the combined sections. g i

It will alsobe noted-that the inner upper edge portions 18 0f the U-shaped spacing member project above the outer portions'of said member, to provide for the more conveniently inserting of the lower edge portions-of the inner wall into the groove or recess 19 of said member.

' The upper end portion of the section 6 is similar to the upper end portion of the section 5 to provide for engagement with a register box.

- In use'the various standard sections are 7 joined and locked together and the upper ad- 'justable section istrimmed along its lower edge portions the desired extent to form the total height desired when the parts are all assembledthus providing for utilizing sections of a standard size in fitting installations. which vary in length or height over multiples of the sections.

From the foregoing description it will be seen that the double wall pipe is of very simple construction and is well adapted for the purpose desired.

lVhat I claim as my invention is:

1. A double wall pipe, comprising a section of doublewall pipe having one of its end portions formed with elongated recesses, and another section of double wall pipe having an outer wall which telescopes over the outer-wall of the first mentioned section and having an inner wall which enters the elongated recesses thereof, said outer and inner walls of the second mentioned section adapted to be trimmed at one end to vary the combined length of the sections when assembled together.

2. A double wall pipe, comprising a section of double wall pipe having its inner and outer walls connected together at one end and forming elongated recesses therebetween, and another section of double wall pipe having portions of the inner and outer walls at one end disconnected, said last mentioned outer wall telescoping over the outer wall of the first mentioned section and having an inner wall which enters the elongated recesses, said outer and inner walls of the second mentioned section adapted to be trimmed at one end to vary the combined 'length of the sections when assembled together.

3. A double wall pipe, comprising a section of'double wall pipe having spacing members connecting the inner and outer walls together at one end and forming elongated recesses between said walls, and another section of double wall pipe having portions of the inner and outer walls at one end disconnectedand one of the portions projecting beyond the other, said last mentioned outer wall telescoping over the outer wall of the first mentioned section and having aninner wall which enters the elongated recesses, said outer and inner walls of the second mentioned section adapted to be trinnned at one end to vary the combined length of the sections when assembled together. I

4:. A double wall pipe, comprising a section of double wall pipe having U-shaped spacing members connecting the inner and outer Walls at one end and forming elongated recesses between said walls, and another section of double wall pipe having portions of the inner and outer walls at one end disconnected and the inner wall projecting beyond the outer wall, said last mentioned outer wall telescoping over the outer wall of the first mentioned section and said projecting inner wall portion entering the elongated recesses, said outer wall and the projecting inner wall of the second mentioned section adapted to be trimmed at one end to vary the combined length of the sections when assembled together.

'tion of double wall pipe 5. A double ivall pipe, tion: of double Wall pipe having Usheped spacing portions-connecting the inner and outer wells at one end end forming'elon gated recesses between said walls, one ofthe Walls'fo-rming each ofsaid recesses p'roj'ecfi and another'sec tion of double wall pipe 'hevingportions of 7 "the inner and outer Walls at 'one end disconnected end the inner Well" projecting be ing beyond the outer walls,

yond the outer wall, sziidlest mentioned outer Wall telescoping over the outer Wall combined length of, the sections When, as

wall portions inclined inwardly in aiseries of Copies of this patent may be obtained for flirecents each, by aiidressing the doinmi sisionerf of i'eteiitii, I

comprising a sec' Y forming stop shoulders,

members interposed between t-hejinnerwall the projecting comprising a 'sec-f having the outer portions" and the inclined ing portions of the inner and outer Walls at one end diseonnectedand the-inner Wall *engl s towerd the inner'gwall portiQns end u-shapedspii ingflw i n POrtionsfof the outer Wall andconnected theretoyand'iorimfl r I ing elongated recesses between. said ,Walls, and'e'nother sectionof'double walLpipehaw 3 projecting beyond the outer Well, said outer wallftele'scoping over (the inwardly inclined tion'edsection and seid-proj eating inner Well portions-of the outer wall 'of the ifirst men I portion entering the elongated recesses, said" O-Lttffifld the projecting inner walls of the v I second mentioned section adapted toz be length ofi the sections When assembled: to- A .gethei: V I i-testimony whereof, Ia flix my signature CHARLES 1 BULLERY tr mmed atone end to vary thecombined 

